Interlocking system for railroads



Oct. 29,1929- J. E. STEPHENSON INTERLOCKING SYSTEM FOR RAILROADS FiledMarch 27, 1926 Hal "LIT.

3B 35 mag Patented Get. 29, 192@ 1,733s8tif a JAMES-E.STEPHENSON,*OlWBOCHESTFE, 1012K, IKSSIGIIGEQTD :RAILWAY SIGN-AL'GOMPANY, 0E ROCHESTEE, EZ'EVT Y INTERLOCKING srsrnra For. narrinoensApplication filed. March 27,1925. "Serial- No. 97,911.

- vices oii of the same lever.

In accordance with v the present invention, it is proposed to constructan interlocking lever usableinxconnection with dynamic indicationapparatus sov as to have, a normal middl'eposition and two reverseextreme positions, soas to make itin fact athree position lever. vMorevspecifically, it isproposed to construct-.an-interlocking lever havingan indicating'latch i'orci-bly moved :to its latchingposition asthelever is moved in either direction from its norm alposition, to.provide a latch dog whichis forcibly driven into its latch engagingposition as the lever is moved fromits normal middle position in eitherdirection, and to provide the necessary contacts to complete thenecessary control and'dynamic indication circuits.

. Other objects, purposesand characteristic features of the inventionwill-appear as'the description thereof progresses.

Tn describing the invention in detail referencewill be made to theaccompanying drawings, in which Fig. 1. shoWs-anovel interlocking systemaccording to the present invention, wherein two signal circuits arecontrolled by a single lever and in whichthe principle or dynamicindication is employed; 7

Fig. 2 illustrates the lever shown in Fig.

'1 to .awlarger scale; and

Fig. '3 illustrates a transverse section o'f the lever-taken on the line3-3 of Fig. 2 as viewed in the direct-ion of the arrows. v

In order to simplify-the description of the present invention, themechanism of the signals whereby dynamicindication currentis generatedhas not been shown speciiicallynnd for this reason itis considered expe'dientto briefly review; the principle of "dynamic indication. 1ninterlocking practice, airs-eon. siderecl highly essential thattheindication current shall, ii flpossi'ble, 'b.edistinctive l5 om thecontrol current so that "the. 'intlicat'n current cannot readily,-or-even possibly-{flow as a result of 'a cross,-or 'the liikef Als'o,thesource of indication currentjiiipossible, should not be present "'untilthe traific'con trolling device has responded to" the changed positioninthe lever anther-owes In aecordance with K the dynamic indic'ation*pri'r ciple, both of these essentials are taken care of by requiringthe 'trafiic' controllin'g clevice' itself to generate the, dynamicindication-cunrent afi'e'r it has practically completed its movement inresponse 't-o-a change i n the-positionof the lever; further, in havingthis tra -fiic contrdll'ing- 'd'eivice generate "a car rent ofdistinctive-polar i y, distinctivephasa if alternating currentfis us'ed,or the {like For further in formation regarding dynainic indicationsystems or the ty e mentioned rererence naybe had to-the p'aterrt' itoFran-k Benedict No. 1,533,357 April] 14, 1925' the application of-P.Rice Ser. #624,265 fi'ledMarChIO, I923. I I V It the lever in such a-'dynamic indication system controls a signal, cl e case 'in the embodimnt o t'ilre'i-nvention strated in Fig. 1, the signal is: operatedto't'he-clearpo sition by the application. current-to its con trolwire,and if'the signal is to be returned to its normal position, the-sourceof energy is disconnected, from the control wire, and the control Wireis'connected toganfindication magnet on the lever. l/Vlren fihe signal.has

almost completeditsretnrn movement, a circult 18 completed througl'ithisind-icatioa magnet'in which currentiioivs, due-to regeneration as'taresultiof the signal moving, by 9 gravity,':a spring, or both,toitsnorrnal dane ger position rthe dynamicallygenerated nurrent flowingin the same direction through I the control wire as that flowing in' thecontrol wire when the signal is cleared.

Structure Referring to Fig. 1, the invention has been shown inconnection with a lever L controlling the entering (westbound) signal Zat the approach to a siding 1, the leaving (eastbound) signal Z of suchsiding, and the leaving (eastbound) signal Z of the main track 2 of suchsiding, this siding including a manually or power operable switch S. Thecontrol wire 3 leads directly to the signal Z, and the control wire 4leads to the signal Z or the signal Z through wires 5 and 6,respectively, depending on the position of the switch box contact 7controlled by the switch S.

Referring to Fig. 2, the control lever L comprises a main bar or lever10 which is slidably supported between the frame pieces 11 and 12, (seeFigs. 2 and 3), and is held down by a top plate 13 upon the interlockingframe portions 14 and 19.

This lever L is connected by a rod 15 to a contact block 16 forcontrolling the control and dynamic indication circuits, morespecifically described hereinafter. This main bar 10 is thus slidablysupported for endwise movement, and by the provision of the Z- shapedcam slot 17 is adapted to move the roller 18 up and down as the lever ispulled out and pushed in, respectively. This roller 17 operates theusual tappet bar of the interlocking machine, familiar to those skilledin the art.

The lever 10 has notches cut in its lower portion, leaving a lock lug20, latch lugs 21 and 22, and a cam operating lug 23. Directly belowthis lever portion 10 and in the main frame of the interlocking machineis mounted an indication latch 25, pivotally supported by the pin 26,and spring pressed to its normal position as shown by the spring 27,this latch being adapted to be locked in its abnormal position by theindication dog 30 pivotally supported at 31 and 5 ring pressed to itslatch engaging position y the free end of ti e same spring 27. Directlybelow the indication dog 30 is an indication magnet IllLha'ving anarmature 33, which magnet if energized operates the latch to itsdisengaging po sition through the medium of a pm, as shown. Directly inback of the indication dog 30 is supported an indication cam 35, whichis pivotally supported at 36, and is spring pressed to its normalposition by the spring 37 contained on the spring plunger 38 slidablysupported in the hole 39.

The mechanism just described is the well known indication lockingmechanism which may be automatically unlocked by the indica- In additionto this locking mechanism, there is provided a lever latching meanswhich is manually controlled by turning the handle 40. In the particulararrangement shown, this handle 40 is fixed to the rocking plunger 41 bya pin or screw 42. This tion 13 of the top handle 40 is normally held inits upright position by a spring 43, secured within the hollow portionof the rear end of the lever 10, and having its other end fastenedthrough the head of a screw 44 fastened in the rocking plunger 41. Thisrocking plunger also has a collar 45 pinned thereto to prevent endwisemovement thereof. To the upstanding porplate 13, is secured by screws 51and 52, the slot structure 50, of a bayonet slot arrangement. This slotstructure (see Fig. 3) contains a hole through which the rocking plunger41 is adapted to slide as the lever 10 is moved back and forth, a keyway54 being provided to allow one or the other of the keys 55 and 56 fixedto the plunger 41, to slide therethrough, depending on whether thehandle 40 is tilted toward the right or toward the left, and whether thehandle is pulled or pushed from its normal position. In order to aid theoperator in tilting the handle 40 to the proper inclined position toregister the key 55 or 56, as the case may be, with the keyway 54, lips50 and 50 extending from the structure 50, have been provided, theupstanding portion 13 being hollowed out to provide clearance for thelip 50.

' Operation If the operator wishes to clear the signal Z, he turns hislever toward the right and then pushes the same. This causes the latchlug 22 to push the indication latch to its locked position, so that theprojection 25' thereof moves upward on the left side of the lock lug 20.Upon further movement of the lever toward the right, the lock lug 20engages the indication cam 35, thereby causing it to operate theindication dog 30 (if this has not already been operated by the end ofspring 27), thus assuring that the indication latch is in its lockedposition. finally reached its extreme right hand position, a circuit iscompleted from the terminal 13 of a suitable source of energy, contact57 of the cross-protection relay, wires 58 and 59, through contacts 60and 61, wire 3, the operat ing motor of the signal Z, to a common returnwire C connected to the other side of said source of energy. This causesthe signal Z' to assume its clear or proceed position.

After the train has passed the signal, the, operator should not be ableto return the dog 30 was previously forced to its engaging position.Further movement of the lever to- When the lever has signal-Z, wires 8.and '63,.contacts 6 l and'65,

wires '66 and 67, coilsof-theindication net 1M, wire 68,cross-protection relay CR, wire 69, to the common return wireC fromwhich we started. 'VVhen the signal Z has almost reached its dangerposit-ion, the mechanism of the signal completes a dynamic indicationcircuit, whereby the motor of the signal Z generates current which flowsthrough-theindication circuit just traced and causes operation of 'theindication magnet IM, this current being in a direction (assuming adirect current system) so as not to. operate the cross-protection relayCR. This cross-protection relay OR, in a direct current system, is apolarized device,'and trips the contact 57 only if current flows as aresult of 'the applicationgof the B terminal to'a part of the circuitsuch as the wire-67. Operation of the indication magnet 1M causesithedog 30to-be movedout of-engagement with the latch -25, allowing thespring 27 to operate the latch; to its nonengaging position, whereby theoperator. is

permitted to move the lever still further toward the left to its-normalposit10n,-in which position the roller 18 unlocks: all conflictinglevers. I

If the operator desires to cleareither the signal Z or the signal Zdepending on .theposition of the switch S, to allowa train to pass, hewill tilt the handle 40 toward the left, thereby allowing the key 56. toenter slot 5 1, after which lie-may pull out the'lever toward the left,and in so doing cause the left hand end Jof the latch 25 to be forceddown by the latch lug 21, this latch lug 21 engagingthe indicationlatch25,therebymoving this latch 25 to its locking position. A

slight further movement of the, lever causes the cam operating lug 23 toengagethe indication cam 35, the operation of which mechanically forcesthe indication dog 30 into i its engaging position, if spring 27'has'not already done so. As the lever Lis moved to the extreme lefthand position, ,a.;circuitfor the signal Z? (assuming the switch S to bein its normal position), may be traced as follows :beginning at the-terminal B, contact 57 of the-cross-protectiondevice'GR,

wires 58 and 62,0ontacts 7 0-65, wireset'and 71, switch box contacts 7,wire 5 ,operating' mechanism of thesignahZv 'to the'commo'n returnwireCr gThe'completion'of this cir- -This flow of current, being theoperator.

euit causes: clearing of the signalZ permitting a train: to :proceedfrom left ito fright' on the main'track 2. i

Let us now: assume that: the train haszpass'ed as follows":beginning atthe-common return wire C, IllEGllflTilSlIl-Of thG signal'Z wire5 contact7 wires 71, t and' 7-2, contacts 60 and 73, wires :74- and 67 winding ofthe indication ma gnet 1M, wire 68, cross-protection relay GRfwire69-back to-the common return wire 0. "When the signal Z has almostreachedits danger positiom by reason-(if the return of the signal "toits stop position by the action of gravityor a spring 'or both;

this indication circuit is completed in the signal mechanism, and thissig'n'al' mechanismcauses indicationcurrent to fiow which operates theindication magnet IM. The flow of this indication current raises thearmature S3 forcibly for an instant, and in so doing disengages the dog30 and allows the l'atch25to again assume itsnormal'posi 7 tion.Asthelever'is returned to its middle normal position, the rollerTlSoperates the tappet bar to a position to unlock all conflictinglevers. Ifthe switch Sis openwhen the lever is moved to'theentremeleft positionthe signal Z" is obviously cleared. instead of signal Z the operationof'which neednotbe specifically considered.

It should be noted that if the wire67 shou'ld'accidentally, (when leverL is imthe position shownin Fip'.

. 1) be connected to the terniinal B of the bat- V tery or other sourceof energ the current 7 due'to such connection couldflow to the sigdue toa cross, or the like,

1 its nals Zand Z and also through the indication magnet and thecross-protection relay.

operate the cross-protection relay, wouldacand the terminal would beentirel-y disconf necte d from "the interlocking systeinbefore v thesignals could be cleared by "such unauthorized current. The raising ofthe latch 74 as av result'of the flow of thisunau'thorized current,allows the spring 75 to "move the contact 57 to its open position, whereit will remain until it is manually'r'estored by Having'thus shown and'clescribedone specific embodiment-of an interlocking system of thedynamic indication type in which [a singleth'ree-pos-i'tion lever maycontrol a plu- '-rality"of -traffic controlling devices, it is-dein adirection to tuate the cross-protection relay very quic'lilv e sired tobe understood that the specific arrangement illustrated has been shownfor the purpose of illustrating the nature of the invention rather thanits scope, and that various changes, modifications and additions may bemade to adapt the invention to a system including a plurality of switchmachines or other traffic controlling devices without departing from thescope of the invention or the idea of means underlying the same.

What I claim as new is 1. In an interlocking system, the combi nationwith a plurality of traffic controlling devices of a single lever forcontrolling the same, a latch dog associated with said lever, said leverbeing movable into either extreme position from its normal middleposition and being locked by said latch dog against movement thereoftoward the middle normal position, and an indication magnet for strikingsaid latch dog so as to move it out of its engaging position when adynamic indication is received from one of said traffic controllingdevices to permit said lever to be returned to its normal position.

2. In an interlocking system, the combination with a lever having anindication latch, of a lock dog for locking said latch and a cam forforcing said dog into engagement with said latch, said lever having amiddle normal position and two extreme positions and having lugs forforcibly operating said latch and said cam into their active positionswhen said lever is moved to either extreme position from the middleposition, an indication magnet which if momentarily energized operatessaid lock dog todisengage said latch, and two electrically operatedtraffic controlled devices capable of generating a dynamic indicationcurrent when they have almost completed their operation in response to achange in the position of said lever toward the normal position.

3. A lever for interlocking machines comprising, a lever bar slidablysupported in a frame, a rock plunger rockahly supported on said leverbar and having its free end slidably supported in stationary meanshaving a slot, a handle for said rocking plunger, and means associatedwith said rocking plunger for preventing said lever from being movedslidably unless said handle is first tilted from its normal position.

4. Locking means for reciprocable levers of interlocking machinescomprising, a shaft s cured tosuch lever in a manner to pe init it to berocked about its axis and so as to i have its axis substantiallyparallel to the direction in which said lever may be reciprocated,stationary means in which said shaft is adapted to slide having a slottherein, and

must be rotated to an extent to line said key up with said slot beforesaid lever may be moved in a certain direction.

5. Locking means for reciprocal levers of interlocking machinescomprising, a shaft secured to'such lever in a manner to permit it to berocked about its axis and so as to have its axis substantially parallelto the direction in which said lever may be reciprocated, stationarymeans in which said shaft is ada ted to slide having a slot therein, andtwo eys projecting out of said shaft on opposite sides of saidstationary means when said lever is in its middle position, said keysbeing out of alignment with each other, whereby said shaft must berocked to different positions to permit said lever to be pulled andpushed respectively.

' 6. An interlocking lever comprising, alever bar supported for slidableendwise movemen-t, a rock shaft supported by said lever bar againstendwise movement With respect to said lever bar and so as to have itsaxis parallel to the direction of movement of said lever bar, a handleon said rock shaft for reciprocating said lever bar, stationary means inwhich said shaft may slide provided with a slot therein, and a keyprojecting from sait shaft out of alignment with said slot so that saidhandle must be tilted to permit said key to entersaid slot before saidlever bar can be moved in a certain direction.

7. An interlocking lever comprising, a lever bar supported for slidableendwise movement, a rock shaft supported-by said lever bar againstendwise movement with respect to said lever bar and so as to have itsaxis parallel to the direction of movement of said lever bar, a handleon said rock shaft for recoprocating said lever bar, stationary means inwhich said shaft may slide having a slot therein, and two keysprojecting from said shaft on opposite sides of said stationarymeans-when said lever is in its middle position, said keys being out ofalignment with each other, whereby said handle must be tilted in onedirection or the other as the lever bar is operated'in one direction orthe other.

8. In an interlocking system. a three position lever for controlling twoelectrically operated traffic controlling devices, the middle positionof said lever putting both of said devices in their normal condition,movement to oneextreme position of said lever putting one of saiddevices in its abnormal condition, and movement of the lever to itsother extreme position putting'the other of said devices in its abnormalcondition; and manually operable mechanical means for preventing saidlever from being moved from one extreme position to the other extremeposition by a single movement. 1

9. In an interlocking system, a three position lever for controlling twoelectrically locking means by current generated dynam ically by one orthe other of said traflic controlling devices depending on from whichextreme position said lever has been moved to the middle position.

10. In an interlocking system, a three po sition lever for controllingtwo electrically operated traflic controlling devices, the normalposition of said lever putting both of said devices in their normalcondition, movement of said lever to one extreme position putting one ofsaid devices in its abnormal condition, and movement of said lever toits other extreme position putting the other of said devices in itsabnormal condition; and means for checking said lever against movementto the normal position by dynamic indication current derived from thetra'flic controlling device last changed.

11. In an interlocking system of the electrically operated dynamicindication type, a three position lever for independently operating twotraffic controlling devices, and means for checking said lever againstmovement to the normal position by dynamic indication current derivedfrom the trafiic controlling device last operated.

.12. In an interlocking system, in combination, a plurality of tratficcontrol devices capable of generating indication current, a singlecontrol lever for the same having a normal and a plurality of reversepositions, and latch means, responsive to said indication current, forpreventing movement of the lever to the normal position.

13. In an interlocking system, in combination, aplurality of trafficcontrol devices, a single control lever for the same having a normal anda plurality of reverse positions, latch means for preventing movement ofthe lever to the normal position, and release means for said latchmeans, operable by dynamic indication current, for allowing movement ofthe lever to its normal position.

14. In an interlocking system, in combination, two trafiio controldevices, a single lever for controlling the devices, energizing circuitsfor said devices, a check relay controlling s'aid circuits, andenergizing circuits for the check relay including contacts controlled bysaid single leverand portions of said ener gizing circuits for thecontrol devices.

15. In an interlocking system, a plurality of trafiic controllingdevlces, a single lever for controlling said devices and having normaland reverse controlling positions, and means, operable by currentgenerated in accordance with the condition of said controlling device,for checking said lever against movement to normal position.

16. In an interlocking system, a plurality of trafiic controllingdevices, a single lever for controlling said devices and having normaland reverse controlling positions, and means to check the lever againstmovement to normal position controlled by dynamic indication currentproduced by one of the traffie controlling devices. v

17 In an interlocking system, a plurality of traiiiccontrolling devices,a single lever for controlling said devices and having normal andreverse controlling positions, and means to check the lever againstmovement to normal position controlled by dynamic indication currentproduced by trafiic controlling means.

18. In an interlocking system, a plurality of traffic controllingdevices, having means for generating an indication current uponsignature.

JAMES E. STEPHENSON.

